1. Field of the Invention
This invention relates to a method for preparing a difunctional aliphatic organic compound. More particularly, the difunctional aliphatic organic compound described herein, e.g., a dicarboxylic acid, diester or a derivative thereof, is produced by a two-step method employing ultraviolet radiation.
2. Brief Description of the Prior Art
In general, methods for producing difunctional aliphatic organic compounds are known. For example, U.S. Pat. No. 4,322,547 discloses a method for preparing a difunctional aliphatic organic compound. The method involves (1) reacting hydrogen peroxide with a cyanoethyl derivative of cycloaliphatic ketone to obtain a hydroperoxide; (2) catalytically splitting the hydroperoxide in an aqueous or aqueous-organic medium by adding a catalyst consisting of ferrous salts and cupric salts to obtain an unsaturated difunctional acid; and (3) catalytically hydrogenating the unsaturated acid in an organic solvent in the presence of a catalyst to obtain the product saturated difunctional aliphatic organic compound. This method is limited to where the cycloaliphatic ketone is cyclopentanone or cyclohexanone.
Another example is U.S. Pat, No. 5,872,267 which discloses a five-step method for making azelaic acid, i.e., a dicarboxylic acid. The method involves (1) adding cyclohexanone to a propionitrile to form 3-(2-cyclohexanonyl)propionitrile; (2) oxidizing the propionitrile to the corresponding lactone, 7-cyanoethyl-2-oxepanone; (3) pyrolyzing the lactone at 450.degree. C.; (4) hydrogenating the pyrolyzed lactone; and (5) hydrolyzing the hydrogenated product to provide the product azelaic acid.
It would be desirable to provide a method for producing a difunctional aliphatic organic compound such as a dicarboxylic acid, e.g., azelaic acid, diester or a derivative thereof which requires a minimum number of steps.